package com.nq.service.impl;

import com.nq.common.ServerResponse;
import com.nq.pojo.User;
import com.nq.service.IUserAgreementService;
import com.nq.utils.PropertiesUtil;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.springframework.web.multipart.MultipartFile;

import com.itextpdf.text.*;
import com.itextpdf.text.pdf.*;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.parser.PdfTextExtractor;
import com.itextpdf.text.pdf.parser.SimpleTextExtractionStrategy;

@Service("iUserAgreementService")
public class UserAgreementServiceImpl implements IUserAgreementService {
    private static final Logger log = LoggerFactory.getLogger(UserAgreementServiceImpl.class);

    @Autowired
    private com.nq.service.IUserService iUserService;

    @Override

// 在generateAgreementPdf方法中修改返回逻辑
    public ServerResponse generateAgreementPdf(HttpServletRequest request) {
        try {
            User user = iUserService.getCurrentUser(request);
            user = (User) iUserService.findByUserId(user.getId()).getData();
            if (user == null) {
                return ServerResponse.createByErrorMsg("用户未登录");
            }

            if (StringUtils.isBlank(user.getRealName()) || StringUtils.isBlank(user.getIdCard()) || StringUtils.isBlank(user.getRegAddress())) {
                return ServerResponse.createByErrorMsg("用户信息不完整，请先完成实名认证");
            }

            // 检查是否已生成PDF
            String pdfDir = PropertiesUtil.getProperty("loca.pdf.dir");

            File dir = new File(pdfDir);
            if (!dir.exists()) {
                dir.mkdirs();
            }

            String pdfFileName = "agreement_" + user.getId() + ".pdf";
            File pdfFile = new File(dir, pdfFileName);
            
            // 构建完整的PDF访问URL
            String pdfUrl = PropertiesUtil.getProperty("pdf.server.http.prefix") + "/agreement_" + user.getId() + ".pdf";

            // 如果PDF已存在，删除后重新生成，确保数据是最新的
            if (pdfFile.exists()) {
                log.info("PDF文件已存在，删除后重新生成: {}", pdfFile.getAbsolutePath());
                boolean deleted = pdfFile.delete();
                if (!deleted) {
                    log.warn("删除旧PDF文件失败: {}", pdfFile.getAbsolutePath());
                }
            }

            // 从资源中读取PDF模板文件
            File pdfTemplate = getTemplateFile("中原证券股票分成协议（电子正式版）.pdf");
            if (pdfTemplate == null || !pdfTemplate.exists()) {
                return ServerResponse.createByErrorMsg("PDF模板文件不存在");
            }

            // 从PDF模板生成新的PDF，替换占位符
            generatePdfFromTemplate(pdfTemplate, pdfFile, user);

            return ServerResponse.createBySuccess(pdfUrl);
        } catch (Exception e) {
            log.error("生成用户协议PDF失败", e);
            return ServerResponse.createByErrorMsg("生成PDF失败：" + e.getMessage());
        }
    }
    /**
     * 从PDF模板生成新的PDF，替换占位符
     */
    private void generatePdfFromTemplate(File templatePdf, File outputPdf, User user) throws Exception {
        log.info("开始生成PDF，模板路径: {}, 输出路径: {}, 用户: {}", 
                templatePdf.getAbsolutePath(), outputPdf.getAbsolutePath(), user.getId());
        
        PdfReader reader = null;
        PdfStamper stamper = null;
        FileOutputStream fos = null;
        
        try {
            reader = new PdfReader(new FileInputStream(templatePdf));
            fos = new FileOutputStream(outputPdf);
            stamper = new PdfStamper(reader, fos);

            // 设置中文字体
            BaseFont baseFont = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
            Font font = new Font(baseFont, 12, Font.NORMAL);
            Font boldFont = new Font(baseFont, 12, Font.BOLD);

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日");
            String currentDate = sdf.format(new Date());

            // 准备替换的数据
            String realName = user.getRealName() != null ? user.getRealName() : "";
            String idCard = user.getIdCard() != null ? user.getIdCard() : "";
            String address = user.getRegAddress() != null ? user.getRegAddress() : "";
            
            log.info("PDF生成数据 - 姓名: {}, 身份证: {}, 地址: {}", realName, idCard, address);

            // 获取PDF页数
            int pageCount = reader.getNumberOfPages();
            log.info("PDF模板页数: {}", pageCount);

            // 在每一页上查找并替换占位符
            for (int pageNum = 1; pageNum <= pageCount; pageNum++) {
                PdfContentByte canvas = stamper.getOverContent(pageNum);
                Rectangle pageSize = reader.getPageSize(pageNum);

                // 提取PDF文本查找占位符位置
                String pageText = PdfTextExtractor.getTextFromPage(reader, pageNum, new SimpleTextExtractionStrategy());

                // 在PDF上查找并替换占位符
                replacePlaceholdersInPdf(canvas, pageSize, pageText, realName, idCard, address, currentDate, font, pageNum);
                log.info("已处理PDF第{}页", pageNum);
            }

            stamper.close();
            stamper = null;
            reader.close();
            reader = null;
            fos.close();
            fos = null;
            
            // 验证生成的文件
            if (outputPdf.exists()) {
                long fileSize = outputPdf.length();
                log.info("PDF生成完成，文件路径: {}, 文件大小: {} 字节", outputPdf.getAbsolutePath(), fileSize);
                if (fileSize == 0) {
                    throw new Exception("生成的PDF文件大小为0");
                }
            } else {
                throw new Exception("PDF文件生成失败，文件不存在");
            }
        } catch (Exception e) {
            log.error("生成PDF失败", e);
            throw e;
        } finally {
            if (stamper != null) {
                try {
                    stamper.close();
                } catch (Exception e) {
                    log.error("关闭stamper失败", e);
                }
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (Exception e) {
                    log.error("关闭reader失败", e);
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (Exception e) {
                    log.error("关闭输出流失败", e);
                }
            }
        }
    }

    /**
     * 在PDF上替换占位符（使用文本覆盖方式）
     */
    private void replacePlaceholdersInPdf(PdfContentByte canvas, Rectangle pageSize, String pageText,
                                         String realName, String idCard, String address, 
                                         String currentDate, Font font,int pageNum) throws Exception {
        // 查找占位符在文本中的位置，然后估算在PDF中的坐标
        // 由于PDF坐标系统复杂，这里使用固定位置替换
        // 实际使用时需要根据PDF模板的具体布局调整坐标
        float margin = 50;
        float lineHeight = 14;
        float startY = pageSize.getHeight() - 194;

        if(pageNum == 1){
            replacePlaceholder(canvas, "", realName, margin + 75, startY, 0, font);
            startY -= lineHeight;

            replacePlaceholder(canvas, "", address, margin + 75, startY-2, 0, font);
            startY -= lineHeight;

            replacePlaceholder(canvas, "", idCard, margin + 95, startY-2, 0, font);
        }
        if(pageNum == 3){
            replacePlaceholder(canvas, "", currentDate, margin + 60, startY+32, 0, font);
            replacePlaceholder(canvas, "", currentDate, margin + 60, startY, 0, font);
        }

    }

    /**
     * 替换单个占位符
     */
    private void replacePlaceholder(PdfContentByte canvas, String placeholder, String value,
                                   float x, float y, float width, Font font) {
        // 添加白色背景覆盖占位符区域
        canvas.saveState();
        canvas.setColorFill(BaseColor.WHITE);
        canvas.rectangle(x - 5, y - 15, width, 20);
        canvas.fill();
        canvas.restoreState();

        // 添加新文本
        ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT,
                new Phrase(value, font), x, y, 0);
    }

    @Override
    public void viewAgreementPdf(HttpServletRequest request, HttpServletResponse response) {
        FileInputStream fis = null;
        OutputStream os = null;
        try {
            User user = iUserService.getCurrentUser(request);
            if (user == null) {
                response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "用户未登录");
                return;
            }

            String pdfDir = PropertiesUtil.getProperty("loca.pdf.dir");
            String pdfFileName = "agreement_" + user.getId() + ".pdf";
            File pdfFile = new File(pdfDir, pdfFileName);

            log.info("查看PDF文件，路径: {}, 是否存在: {}, 文件大小: {}", 
                    pdfFile.getAbsolutePath(), pdfFile.exists(), 
                    pdfFile.exists() ? pdfFile.length() : 0);

            if (!pdfFile.exists()) {
                response.sendError(HttpServletResponse.SC_NOT_FOUND, "协议文件不存在，请先生成协议");
                return;
            }

            long fileLength = pdfFile.length();
            if (fileLength == 0) {
                log.error("PDF文件大小为0: {}", pdfFile.getAbsolutePath());
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "PDF文件为空");
                return;
            }

            // 验证PDF文件头
            FileInputStream checkFis = new FileInputStream(pdfFile);
            byte[] header = new byte[4];
            checkFis.read(header);
            checkFis.close();
            String headerStr = new String(header);
            if (!headerStr.startsWith("%PDF")) {
                log.error("文件不是有效的PDF格式，文件头: {}", headerStr);
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "PDF文件格式错误");
                return;
            }
            log.info("PDF文件头验证通过: {}", headerStr);

            response.setContentType("application/pdf");
            response.setHeader("Content-Disposition", "inline; filename=\"" + 
                    new String(pdfFileName.getBytes("UTF-8"), "ISO-8859-1") + "\"");
            response.setContentLengthLong(fileLength);
            response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
            response.setHeader("Pragma", "no-cache");
            response.setDateHeader("Expires", 0);

            fis = new FileInputStream(pdfFile);
            os = response.getOutputStream();

            byte[] buffer = new byte[8192];
            int bytesRead;
            long totalBytes = 0;
            while ((bytesRead = fis.read(buffer)) != -1) {
                os.write(buffer, 0, bytesRead);
                totalBytes += bytesRead;
            }

            log.info("PDF文件传输完成，总字节数: {}", totalBytes);
            os.flush();
        } catch (Exception e) {
            log.error("查看用户协议PDF失败", e);
            try {
                if (!response.isCommitted()) {
                    response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "查看PDF失败: " + e.getMessage());
                }
            } catch (IOException ex) {
                log.error("发送错误响应失败", ex);
            }
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    log.error("关闭文件流失败", e);
                }
            }
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    log.error("关闭输出流失败", e);
                }
            }
        }
    }

    @Override
    public ServerResponse saveAgreementSignature(MultipartFile signatureFile, HttpServletRequest request) {
        try {
            User user = iUserService.getCurrentUser(request);
            if (user == null) {
                return ServerResponse.createByErrorMsg("用户未登录");
            }

            if (signatureFile == null || signatureFile.isEmpty()) {
                return ServerResponse.createByErrorMsg("签名图片不能为空");
            }

            // 保存签名图片到本地
            String signatureDir = PropertiesUtil.getProperty("loca.pdf.dir");
            File dir = new File(signatureDir);
            if (!dir.exists()) {
                dir.mkdirs();
            }

            String signatureFileName = "signature_" + user.getId() + ".png";
            File signatureFileLocal = new File(dir, signatureFileName);
            
            signatureFile.transferTo(signatureFileLocal);
            
            log.info("用户{}的签名图片已保存: {}", user.getId(), signatureFileLocal.getAbsolutePath());
            
            // 重新生成PDF并插入签名图片
            String pdfDir = PropertiesUtil.getProperty("loca.pdf.dir");
            String pdfFileName = "agreement_" + user.getId() + ".pdf";
            File pdfFile = new File(pdfDir, pdfFileName);
            
            if (pdfFile.exists()) {
                // 在PDF第三页插入签名图片
                addSignatureToPdf(pdfFile, signatureFileLocal, user);
                
                // 构建PDF访问地址
                String pdfUrl = PropertiesUtil.getProperty("pdf.server.http.prefix") + "/agreement_" + user.getId() + ".pdf";
                
                // 更新用户表的签合同标记（保存PDF地址）
                iUserService.updateSignedContract(user.getId(),pdfUrl);
            }
            return ServerResponse.createBySuccessMsg("签名保存成功");
        } catch (Exception e) {
            log.error("保存用户协议签名失败", e);
            return ServerResponse.createByErrorMsg("保存签名失败：" + e.getMessage());
        }
    }

    /**
     * 在PDF第三页插入签名图片
     */
    private void addSignatureToPdf(File pdfFile, File signatureImage, User user) throws Exception {
        PdfReader reader = new PdfReader(new FileInputStream(pdfFile));
        File tempPdf = new File(pdfFile.getParent(), "temp_" + pdfFile.getName());
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(tempPdf));

        int pageCount = reader.getNumberOfPages();
        
        // 在第三页插入签名图片
        if (pageCount >= 3) {
            PdfContentByte canvas = stamper.getOverContent(3);
            Rectangle pageSize = reader.getPageSize(3);
            
            // 添加签名图片
            if (signatureImage.exists()) {
                Image image = Image.getInstance(signatureImage.getAbsolutePath());
                // 设置图片大小（根据实际需要调整）
                image.scaleToFit(100, 100);
                // 设置图片位置（使用与addHeaderImageToPdf相同的坐标）
                image.setAbsolutePosition(370, pageSize.getHeight() - 194);
                canvas.addImage(image);
                log.info("签名图片已插入到PDF第三页，位置: (370, {})", pageSize.getHeight() - 194);
            }
        }

        stamper.close();
        reader.close();
        
        // 替换原PDF文件
        if (tempPdf.exists()) {
            pdfFile.delete();
            tempPdf.renameTo(pdfFile);
            log.info("PDF文件已更新，签名图片已插入");
        }
    }

    @Override
    public ServerResponse generateAgreementContractPdf(HttpServletRequest request) {
        try {
            User user = iUserService.getCurrentUser(request);
            user = (User) iUserService.findByUserId(user.getId()).getData();
            if (user == null) {
                return ServerResponse.createByErrorMsg("用户未登录");
            }

            if (StringUtils.isBlank(user.getRealName()) || StringUtils.isBlank(user.getIdCard()) || StringUtils.isBlank(user.getRegAddress())) {
                return ServerResponse.createByErrorMsg("用户信息不完整，请先完成实名认证");
            }

            String pdfDir = PropertiesUtil.getProperty("loca.pdf.dir");
            File dir = new File(pdfDir);
            if (!dir.exists()) {
                dir.mkdirs();
            }

            String pdfFileName = "contract_" + user.getId() + ".pdf";
            File pdfFile = new File(dir, pdfFileName);
            
            String pdfUrl = PropertiesUtil.getProperty("pdf.server.http.prefix") + "/contract_" + user.getId() + ".pdf";

            if (pdfFile.exists()) {
                boolean deleted = pdfFile.delete();
                if (!deleted) {
                    log.warn("删除旧PDF文件失败: {}", pdfFile.getAbsolutePath());
                }
            }

            // 从资源中读取PDF模板文件
            File pdfTemplate = getTemplateFile("中原证券商业核心信息保密协议.pdf");
            if (pdfTemplate == null || !pdfTemplate.exists()) {
                return ServerResponse.createByErrorMsg("PDF模板文件不存在");
            }

            generateContractPdfFromTemplate(pdfTemplate, pdfFile, user);

            return ServerResponse.createBySuccess(pdfUrl);
        } catch (Exception e) {
            log.error("生成用户合同PDF失败", e);
            return ServerResponse.createByErrorMsg("生成PDF失败：" + e.getMessage());
        }
    }

    @Override
    public void viewAgreementContractPdf(HttpServletRequest request, HttpServletResponse response) {
        FileInputStream fis = null;
        OutputStream os = null;
        try {
            User user = iUserService.getCurrentUser(request);
            if (user == null) {
                response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "用户未登录");
                return;
            }

            String pdfDir = PropertiesUtil.getProperty("loca.pdf.dir");
            String pdfFileName = "contract_" + user.getId() + ".pdf";
            File pdfFile = new File(pdfDir, pdfFileName);

            if (!pdfFile.exists()) {
                response.sendError(HttpServletResponse.SC_NOT_FOUND, "合同文件不存在，请先生成合同");
                return;
            }

            long fileLength = pdfFile.length();
            if (fileLength == 0) {
                log.error("PDF文件大小为0: {}", pdfFile.getAbsolutePath());
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "PDF文件为空");
                return;
            }

            FileInputStream checkFis = new FileInputStream(pdfFile);
            byte[] header = new byte[4];
            checkFis.read(header);
            checkFis.close();
            String headerStr = new String(header);
            if (!headerStr.startsWith("%PDF")) {
                log.error("文件不是有效的PDF格式，文件头: {}", headerStr);
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "PDF文件格式错误");
                return;
            }

            response.setContentType("application/pdf");
            response.setHeader("Content-Disposition", "inline; filename=\"" + 
                    new String(pdfFileName.getBytes("UTF-8"), "ISO-8859-1") + "\"");
            response.setContentLengthLong(fileLength);
            response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");

            fis = new FileInputStream(pdfFile);
            os = response.getOutputStream();
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = fis.read(buffer)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            os.flush();
        } catch (Exception e) {
            log.error("查看用户合同PDF失败", e);
            try {
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "查看PDF失败: " + e.getMessage());
            } catch (IOException ex) {
                log.error("发送错误响应失败", ex);
            }
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    log.error("关闭文件流失败", e);
                }
            }
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    log.error("关闭输出流失败", e);
                }
            }
        }
    }

    @Override
    public ServerResponse saveAgreementContractSignature(MultipartFile signatureFile, HttpServletRequest request) {
        try {
            User user = iUserService.getCurrentUser(request);
            if (user == null) {
                return ServerResponse.createByErrorMsg("用户未登录");
            }

            if (signatureFile == null || signatureFile.isEmpty()) {
                return ServerResponse.createByErrorMsg("签名图片不能为空");
            }

            String signatureDir = PropertiesUtil.getProperty("loca.pdf.dir");
            File dir = new File(signatureDir);
            if (!dir.exists()) {
                dir.mkdirs();
            }

            String signatureFileName = "contract_signature_" + user.getId() + ".png";
            File signatureFileLocal = new File(dir, signatureFileName);
            
            signatureFile.transferTo(signatureFileLocal);
            
            log.info("用户{}的合同签名图片已保存: {}", user.getId(), signatureFileLocal.getAbsolutePath());
            
            String pdfDir = PropertiesUtil.getProperty("loca.pdf.dir");
            String pdfFileName = "contract_" + user.getId() + ".pdf";
            File pdfFile = new File(pdfDir, pdfFileName);
            
            if (pdfFile.exists()) {
                addSignatureToContractPdf(pdfFile, signatureFileLocal, user);
                
                String pdfUrl = PropertiesUtil.getProperty("pdf.server.http.prefix") + "/contract_" + user.getId() + ".pdf";

                iUserService.updateSignedAgreement(user.getId(), pdfUrl);
            }
            
            return ServerResponse.createBySuccessMsg("签名保存成功");
        } catch (Exception e) {
            log.error("保存用户合同签名失败", e);
            return ServerResponse.createByErrorMsg("保存签名失败：" + e.getMessage());
        }
    }

    private void generateContractPdfFromTemplate(File templatePdf, File outputPdf, User user) throws Exception {
        PdfReader reader = new PdfReader(new FileInputStream(templatePdf));
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(outputPdf));

        BaseFont baseFont = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
        Font font = new Font(baseFont, 12, Font.NORMAL);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日");
        String currentDate = sdf.format(new Date());
        
        int pageCount = reader.getNumberOfPages();

        for (int pageNum = 1; pageNum <= pageCount; pageNum++) {
            PdfContentByte canvas = stamper.getOverContent(pageNum);
            Rectangle pageSize = reader.getPageSize(pageNum);

            replacePlaceholdersInContractPdf(canvas, pageSize, currentDate, font, pageNum);
        }

        stamper.close();
        reader.close();
    }

    private void replacePlaceholdersInContractPdf(PdfContentByte canvas, Rectangle pageSize, String currentDate, Font font, int pageNum) throws Exception {
        float margin = 50;
        float startY = pageSize.getHeight() - 364;
        if(pageNum == 2){
            replacePlaceholder(canvas, "", currentDate, margin + 320, startY, 0, font);
        }
    }

    private void addSignatureToContractPdf(File pdfFile, File signatureImage, User user) throws Exception {
        PdfReader reader = new PdfReader(new FileInputStream(pdfFile));
        File tempPdf = new File(pdfFile.getParent(), "temp_" + pdfFile.getName());
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(tempPdf));

        int pageCount = reader.getNumberOfPages();
        
        if (pageCount >= 2) {
            PdfContentByte canvas = stamper.getOverContent(2);
            Rectangle pageSize = reader.getPageSize(2);
            
            if (signatureImage.exists()) {
                Image image = Image.getInstance(signatureImage.getAbsolutePath());
                image.scaleToFit(100, 100);
                image.setAbsolutePosition(435, pageSize.getHeight() - 288);
                canvas.addImage(image);
                log.info("签名图片已插入到合同PDF第二页");
            }
        }

        stamper.close();
        reader.close();
        
        if (tempPdf.exists()) {
            pdfFile.delete();
            tempPdf.renameTo(pdfFile);
            log.info("合同PDF文件已更新，签名图片已插入");
        }
    }

    /**
     * 从固定目录获取模板文件
     */
    private File getTemplateFile(String templateFileName) {
        try {
            String templateDir = PropertiesUtil.getProperty("pdf.template.dir");
            if (StringUtils.isBlank(templateDir)) {
                log.error("PDF模板目录配置不存在: pdf.template.dir");
                return null;
            }
            
            File dir = new File(templateDir);
            if (!dir.exists()) {
                log.error("PDF模板目录不存在: {}", templateDir);
                return null;
            }
            
            File templateFile = new File(dir, templateFileName);
            if (!templateFile.exists()) {
                log.error("PDF模板文件不存在: {}", templateFile.getAbsolutePath());
                return null;
            }
            
            log.info("使用模板文件: {}", templateFile.getAbsolutePath());
            return templateFile;
        } catch (Exception e) {
            log.error("获取模板文件失败: {}", templateFileName, e);
            return null;
        }
    }
}